Isolated the problem, now what?
 

Here's what I've done so far:

1. Ran Memtest twice, going thru all 9 steps. Took more than an hour. No problem (even though to be more conclusive, it should have run much longer).
2. Ran Prime95 Torture Test - Blend test < 1 min before hardware error message
3. Ran Prime95 Torture Test - Small FFTs < 13 min before hardware error message

Thinking that either of my Samsung PC2700 512MB RAM sticks were damaged, I decided to test them seperately.

1. Dimm 1: ran Blend for 12 minutes without any problems (Beat the 1 minute record when having both dimms in).
2. Dimm 2: ran Blend for 8 minutes without any problems (Beat the 1 minute record when having both dimms in).
3. Switched both dimms in slot 2 and 3 (they were in slot 1 and 3 before individual tests).
4. Ran Prime95 Blend and got a hardware error < 2 min

Automatically, my motherboard runs both of my twin dimms in dual channel mode, whereas individual dimms are run using single channel mode. I'm thinking that it's the dual channel that is making Prime95 display the hardware error message.

My system specs:
Athlon XP 3000+ (stock speeds)
Asus A7N8X Deluxe BIOS 1007
2x512 MB PC2700 Samsung RAM
Geforce 3 Ti 200
Soundblaster Live value
NEC 3250A Dual Layer Burner
2x120GB 8MB 7200RPM SATA Maxtor HD
1x60GB 2MB 7200RPM Quantum LM HD

BIOS:
Optimal settings (vs. aggressive)
-FSB 167Mhz
-2.5-3-3-7 CAS Timings

[URL=http://www.dstudios.ca/temp/mm5.gif]Motherboard Monitor 5 screen capture[/URL]

Would you think that its the dual channel that is creating the hardware error?

try setting it to single channel mode for mem also relax mem timeings try again then. also try one stick then other.

As I said, I did try individual sticks, which indicated that it worked. It was only when I put both of them, in dual channel, that it didn't work. I appologize for not being clearer.

I'll have to check to see what is needed for running them in single channel. BIOS setting I figure. Could you suggest a better timming in order to give me a hint of what to change (newbie in CAS interpretations).

Thanks!

Memtest86 speeds report should indicate that mem is in single/dual channel config by what the throughput speed is. From what you posted I don't think you yet tried BOTH mem modules BUT in the slots to still give single channel (as opposed to the particular physical slots you must pair up for dual channel). Does THAT work? ie both modules single channel.

Possible make sure ALL your ram sockets are clean of dust etc.

My suggestion would be to slightly increase your RAM voltage if your mobo bios settings support doing this.

The reason is that supplying a given voltage, with one chip is ok, but when you have two in the load is greater which may cause a very slight voltage drop. This could be enough to change operation from stable to borderline.

Well, having 2 dimms in slot 1 and 3 or 2 and 3 runs the memory in dual channel. Which is what Memtest ran under without any hitch. I never tried individual dimms in Memtest just because both, in dual channel, worked.

Now, I have them in slot 1 and 2 which runs them in single channel (BIOS cleaerly indicates this as well as the manual)

Other info on my system:
[URL=http://www.dstudios.ca/temp/cpuz_cpu.gif]CPUZ's CPU Info[/URL]
[URL=http://www.dstudios.ca/temp/cpuz_cpu.gif]CPUZ's Memory Info[/URL]

I'll check for dust in the case and will clean the slots with compressed air. Will check the RAM voltages too. Thanks for the tip! So, the new CPU would suck more energy than the old one, thus robbing the memory of some power?

I tried Prime95 having both dimms in single channel mode (slot 1 and 2) and it still gave me the error message. So, having both dimms in, either dual or single channel, seems to cause instability in my system...

Note: 3 times this morning, the case temps have gone from 26C to 106C? MM5 freaks out and stuff...

hmm try turning off mbm5 for a bit and run prime95 wonder if its causeing errors.

Thanks for the hint! I just tried it without MM5 running:

FATAL ERROR: Resulting wum was -3.914402764883792e+028, expected: 9.6197848261e+016
Hardware failure detected, consult stress.txt file.
Torture Test ran 0 minutes - 1 error, 0 warnings.
Execution halted.

This is the error message that I get across the board in all my test... just different numbers maybe.

I increased the "DDR Reference Voltage" from 2.6V to 2.7. I then booted and ran Prim95. As soon as I got in the app, it rebooted my whole system. I guess that wasn't it?

Do you have an adequate power supply? I think you need at least a 300 W unit.

Is your system stable when not running GIMPS?

What kind of heat-sink do you use? What's your CPU temperature under the full load? 52C appearing in your MBM screen capture sounds too low for a full load temp...

Try underclocking your CPU to half speed and running the tests.
This will reduce heat and power usage by the CPU.

Try using slower memory timings. Perhaps 3-4-4-8 and see if it stabilises.